A system includes at least one sensing unit, the sensing unit including a sensing element. The system includes at least one spatial Lorentz filter coupled to the sensing element. The spatial Lorentz filter (SLF) includes an input coupled to the sensing element and an analog to digital converter (ADC) providing a filtered output signal. The sensing unit is connected to a processor configured for determining velocity or position with respect to a magnetic field and/or a geographic position by processing SLF output signals.

The present invention is a method for simultaneously measuring magnetic/magnetic gradient and gravitational fields using atom interferometers includes the steps of releasing laser cooled atoms from a trap, further cooling the released atoms, launching the atoms vertically, preparing the atoms into well-known atomic states, measuring gravity from the atoms as the atoms travel upward, and measuring the magnetic field of the atoms the begin to fall.

A system method and computer-readable medium for correcting measurements obtained by a down hole tool for residual measurement errors is disclosed. A down hole tool having at least two directional field sensors is disposed in a borehole. The at least two directional sensors are substantially orthogonal to each other and to a longitudinal axis of the down hole tool. Measurements are obtained from the at least two directional sensors during rotation of the tool by at least 360 degrees around the longitudinal axis of the tool. Residual measurement errors are determined for the obtained measurements, and a quality level of the determined residual measurement errors selected. The determined residual measurement errors are applied to the obtained measurements when the determined residual measurement errors are consistent with the selected quality level. In various embodiments, the residual measurement errors are reduced from a first value that does not match the selected quality level to a second value that are consistent with the selected quality level.

The invention discloses an air-ground integrated geomagnetic field combined observation method and system. The method comprises the following steps of validating local geomagnetic field model parameters using the geomagnetic field data collected by a mobile earth station before the geomagnetic field survey mission is executed; getting a dynamic model along the flight path using the geomagnetic field data collected by the airborne console over the flight path and the model parameters when the geomagnetic field survey mission is executed; getting a measuring error model along the flight path using the attitude measuring error obtained by the airborne console when the aircraft flies as per the preset attitude; getting the estimation of the geomagnetic field data collected over the flight path in a geographic coordinate frame using the dynamic model and the measuring error model. In the invention, the measuring accuracy of a geomagnetic field vector expressed in the geographic coordinate frame can be improved, and the geomagnetic field anomaly detection can be implemented.

The invention discloses an air-ground integrated geomagnetic field combined observation method and system. The method comprises the following steps of validating local geomagnetic field model parameters using the geomagnetic field data collected by a mobile earth station before the geomagnetic field survey mission is executed; getting a dynamic model along the flight path using the geomagnetic field data collected by the airborne console over the flight path and the model parameters when the geomagnetic field survey mission is executed; getting a measuring error model along the flight path using the attitude measuring error obtained by the airborne console when the aircraft flies as per the preset attitude; getting the estimation of the geomagnetic field data collected over the flight path in a geographic coordinate frame using the dynamic model and the measuring error model. In the invention, the measuring accuracy of a geomagnetic field vector expressed in the geographic coordinate frame can be improved, and the geomagnetic field anomaly detection can be implemented.

A position determination device comprises data input circuitry configured to obtain magnetic field sensor data sensed by a magnetic field sensor, separation circuitry configured to separate the obtained magnetic sensor data into low frequency sensor data including frequencies below a frequency threshold and high frequency sensor data including frequencies above the frequency threshold, fingerprint combining circuitry configured to determine a combined magnetic fingerprint based on the low frequency sensor data and the high frequency sensor data, and position determination circuitry configured to determine the sensor position of the magnetic field sensor by comparing the combined magnetic fingerprint with a magnetic map.

A position determination device comprises data input circuitry configured to obtain magnetic field sensor data sensed by a magnetic field sensor, separation circuitry configured to separate the obtained magnetic sensor data into low frequency sensor data including frequencies below a frequency threshold and high frequency sensor data including frequencies above the frequency threshold, fingerprint combining circuitry configured to determine a combined magnetic fingerprint based on the low frequency sensor data and the high frequency sensor data, and position determination circuitry configured to determine the sensor position of the magnetic field sensor by comparing the combined magnetic fingerprint with a magnetic map.

An apparatus includes an outer structure body having an inner surface defining a cavity and an inner structure body rotatably supported within the cavity. The inner structure body has an outer surface in opposing relation to the inner surface and a central bore. Movable elements are positioned along the inner surface and movably coupled to the outer structure body. Ball elements are positioned along the outer surface and coupled to the inner structure body for movement with the inner structure body. The ball elements releasably contact the movable elements and impart motion to the movable elements in response to relative motion between the inner structure body and the outer structure body. Energy harvesters are positioned to generate electrical charges based on piezoelectric effect or magnetostrictive effect when motion is imparted to the movable elements by the ball elements.

In some embodiments, an apparatus and a system, as well as a method and an article, may operate to acquire a first signal from a first magnetometer at least partially disposed within a Helmholtz coil, to acquire a second signal from a second magnetometer having a sensitivity at least one thousand times less than the first magnetometer, to process the second signal to determine a drive signal, to drive the Helmholtz coil using the drive signal so as to null an ambient Earth magnetic field surrounding the first magnetometer, and to process the first signal as one of a down hole location signal or a down hole telemetry signal, the location signal to determine a range to a sub-surface object, and the telemetry signal to provide data from down hole drilling operations. Additional apparatus, systems, and methods are disclosed.

In some embodiments, an apparatus and a system, as well as a method and an article, may operate to acquire a first signal from a first magnetometer at least partially disposed within a Helmholtz coil, to acquire a second signal from a second magnetometer having a sensitivity at least one thousand times less than the first magnetometer, to process the second signal to determine a drive signal, to drive the Helmholtz coil using the drive signal so as to null an ambient Earth magnetic field surrounding the first magnetometer, and to process the first signal as one of a down hole location signal or a down hole telemetry signal, the location signal to determine a range to a sub-surface object, and the telemetry signal to provide data from down hole drilling operations. Additional apparatus, systems, and methods are disclosed.